Morgan Stanley’s two most senior commodities traders have lost their jobs for using WhatsApp and other unauthorised messaging platforms, reflecting Wall Street’s continued clampdown on communications channels that it cannot monitor.

Nancy King, Morgan Stanley’s global head of commodities, and Jay Rubenstein, the bank’s head of commodities trading, are both leaving the bank after a probe into their use of unauthorised communications systems, according to a person familiar with the situation.

Their departures, which were previously reported by commodities news site SparkSpread, follow JPMorgan Chase’s suspension of one of its top credit traders in January over his use of WhatsApp. That credit trader, Edward Koo, has since left the bank, a person familiar with the situation said.